Cryptology ePrint Archive: Report 2010/076

Private and Continual Release of Statistics

T-H. Hubert Chan, Elaine Shi, Dawn Song

Abstract: We ask the question Ė how can websites and data aggregators continually release updated statistics, and meanwhile preserve each individual userís privacy? Suppose we are given a stream of 0ís and 1ís. We propose a differentially private continual counter that outputs at every time step the approximate number of 1ís seen thus far. Our counter construction has error that is only poly-log in the number of time steps. We can extend the basic counter construction to allow websites to continually give top-k and hot items suggestions while preserving usersí privacy.